<script>
  function ajax01(url,successFn){
    const xhr = new XMLHttpRequest();
    xhr.open("get",url,false)
    xhr.onreadystatechange = function(){
      if(xhr.readyState == 4){
        if(xhr.status === 200){
          successFn(xhr.responseText)
        }
      }
    }
    xhr.send();
  }

  ajax01("http://www.xxx.com/newlist",function(res){
    console.log("res:",res);
  });
</script>